Microbial oxidation of lithospheric organic carbon in rapidly eroding tropical mountain soils

Microbes eat rocks and leave carbon dioxide The reaction of atmospheric carbon dioxide (CO 2 ) with silicate rocks provides a carbon sink that helps counterbalance the release of CO 2 by volcanic degassing. However, some types of rocks contain petrogenic organic carbon, the oxidation of which adds CO 2 to the atmosphere, counteracting the drawdown by silicates. Hemingway et al. present evidence from the rapidly eroding Central Range of Taiwan showing that microbes oxidize roughly two-thirds of the petrogenic organic carbon there and that the rate of oxidation increases with the rate of erosion. Science , this issue p. 209